"""
Observer.py

Author: Miles Malerba
Date: 9-22-08
"""

class Observer(object):
    """this class acts as the observer in the observer pattern.
       it allows classes that extend this class to register with observables
       to recieve updates when changes occur
    """
    
    def update(self,subject, param):
        """update the observer when the subject changes"""
        raise NotImplementedError('method not implemented')
